System Requirements for Building a Standby CommServe Host
To build the standby CommServe host by using failover configurations, your environment must meet the following mandatory requirements:
This setup requires three Windows Server computers to host the following software:
- The production CommServe host
You can also use an existing production CommServe host for the configuration.
- The standby CommServe host
- The MediaAgent software (to backup and restore SQL Server agent data) in the standby CommServe location
Additional Requirements for Advanced Configuration
For advanced configurations, you also require a minimum of three Windows Server hosts additionally to configure the witness server roles. The three witness server roles must reside at the standby CommServe location. You can also use the existing MediaAgent computer at the standby CommServe location to configure the witness server role.
For high availability of witness servers during a disaster, you must configure five witness server roles. In addition to the three witness server roles at the standby CommServe location, you can configure the witness server on the production and standby CommServe computers.
You must meet the following software requirements for CommCell disaster recovery failover:
|Domain Name System (DNS)|| Use a primary DNS server that reside in the standby CommServe location or in a location not affected by a disaster at the production site.
For advanced failover configurations, the DNS Server role must be installed on both the production and standby CommServe hosts. This enables the dnscmd.exe command, which associates the IP addresses of the production and standby CommServe hosts with the floating CommServe host name in the DNS.
Alternatively, if you plan to use scripts to update the DNS, you do not require a DNS role on the CommServe hosts.
|Proxies (to route requests and responses between the CommServe and proxy-enabled clients)||One of the proxies must reside at in the standby CommServe location or at in a location not affected by a disaster at the production site.|
|Internet Protocol version||Use the IPv4 protocol version. IPv6 Internet Protocol version is not supported for this setup.|
|System time||The system time on both the production and standby CommServe hosts must be synchronized.|
Also, see System Requirements for these components:
If the CommServe and MediaAgents include Service Pack older than Service Pack 7, the deduplication databases are sealed after each CommServe failover and a new baseline is written on the disk library mount paths. Therefore, to accommodate the new baseline backups after each CommCell failover, ensure that double the disk library storage is provisioned.
However, if the CommServe and MediaAgents include Service Pack 7 or later, the deduplication databases can be resynchronized instead of sealed, which makes the storage space requirement for baseline backups unnecessary.
This setup requires the following licenses based on the SnapProtect license type:
- A SnapProtect traditional license requires licensing the Microsoft SQL Server agent.
- Dual IP License
The CommServe license supports two IP addresses: one for the production CommServe host, and another for the standby CommServe host. By having two IP addresses, you can identify the appropriate CommServe when the production CommServe metadata is restored on the standby CommServe host.